The present invention relates to fasteners and fastener drivers and, more particularly, to a fastener and fastener driver which are configured to retain the blade of the fastener driver in the slot in the head of the fastener.
Screws or fasteners and the drivers to rotate the screws or fasteners are known in the art. Typical fastener head configurations include a standard slotted head fastener and a Phillips head fastener. The fastener head shape may be round, flat, or oval, for example. The shape of the slot in a fastener head is square or rectangular with the sides perpendicular to the bottom, and the width of the slot extending all the way across the fastener head. The shape of a Phillips head is generally in a symmetrical cross with the sides tapering to a point in the center of the cross. The width and depth of the slot and Phillips head may vary according to industry standard sizes.
The standard straight-blade screw driver has a flat tip which tapers from the screw driver shank to the tip. A standard Phillips screw driver has a tip which also tapers from the shank to the tip and the tip is cross shaped to fit in the Phillips head screw. The tip sizes of these screw drivers are according to industry standards to fit the corresponding screw head.
A common problem with these screws and screw drivers is the shape of the slot and cross along with the shape of the related screw driver tip creates a force which pushes the screw driver tip away from the screw head and results in the screw driver slipping. The user of the screw driver must apply a counter force to overcome this force to push the tip of screw driver into the head when tightening or loosening a screw. If the torque required to drive the screw into a substraight material is greater than the user's force pushing the tip of the screw driver into the slot of the screw head the tip of the screw driver slips out of the screw head damaging the screw and/or substraight. Additionally, a flat blade screw driver tends to slip along the length of the slot with the same results.